Reflex klystron



May 2l, 1946. n. G. CLIFFORD REFLEX KLYS TRON Filed Jan. 20, 1943 lll/111i afina/fall INVENTOR ATTORNEY Patented May 2l, 1946 REFLEX KLYSTRON David Gordon Clifford. Palo Alto, Calif., assigner to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application January 20, 1943. Serial No. 472,982

(Cl. 25o-27.5)

4 Claims.

This invention relates to electron discharge devices. and more particularly to the type thereof used for generation of ultra high frequency oscillations, and is an improvement upon the structure disclosed in U. S. patent application, Serial No. 425,715, of Ernest C. Okress assigned to the same assignee as the present application.

The prior art exemplified by the copending application above mentioned involves the use of dual cavities or hollow body resonators of which one is used as a. so-called buncher and the other as a catcher. Tuning such a device involves provision and use of a tracking tuner that resonates each cavity to the proper frequency. By reference to said copending application, it will become immedlately evident that manufacturing and assembly dimculties are encountered and the device is bulky and expensive and objectionable from the standpoints of critical tuning and insuiiicient power output efficiency.

The present invention has for a general object the provision of a generator improving upon the prior art construction both mechanically and as to output efficiency.

Another object of general nature is to provide a generator capable of developing relatively high power in the ultra high frequency band.

A further object of the invention is to simplify the tuning of a generator as characterized.

Yet another object of the invention is to utilize the beneficial effects of coaxial construction of resonator for dual purpose of buncher and catcher and at the same time employ extensive cathode and grid areas.

Still further objects of the invention will appear as the description progresses, both by direct recitation thereof and by implication from the context.

Referring to the accompanying drawing in which like numerals of reference are used to designate similar parts in the views employed to illustrate an embodiment of the invention;

Fig. l is a longitudinal sectional view of the major part of an electron discharge device of the ultra high frequency generator type embodying the present invention; and

Fig. 2 is a cross-sectional view on line II--II of Fig. l.

In the speclilc embodiment of the invention illustrated in said drawing, the reference numeral III designates an evacuated housing or envelope an end portion I I whereof is of glass and sealed, in practice, with appropriate stem (not shown) for the illament and other lead-in wires. Said glass end portion is preferably of a generally cylindrical shape and has its forward end sealed on the marginal end of a metallic cylindrical body portion I2 in turn secured at its forward end vacuum tight to a cylindrical outer metallic wall I3 for a resonator chamber Il. This resonator chamber is, in appearance. an outer tube-like chamber section Il between said outer wall I3 and another cylindrical metallic wall It concentric therewith and of smaller diameter, and an -inner tubular chamber section Il. between a yet smaller diameter cylindrical metallic wall Il and a central metallic post I9. Between the two cylindrical walls IB and I8 of di'erent and smaller dlameters than outer wall I 3, is an annular or tubelike ileld-free space 20. Furthermore, these two smaller-diameter cylindrical walls I6, I8 end within the resonator chamber, and opposed in spaced relation therefrom but virtually as continuations thereof are two other metallic walls 2| and 22 coaxially situated and of same diameters as said walls I6 and I8 respectively. The gap or constriction 23 between the near ends of said walls I6 and I8 and walls 2I and 22 radially connects the two chamber sections I5 and Il. This gap or constriction 2l is adjustable in an axial direction for tuning purposes by means hereinafter described.

Within the region enclosed by the metallic cylindrical body portion I2 above mentioned as sealed to the glass portion and forming part of the envelope, is an annular cathode 24 situated opposite the end of the annular or tube-like fieldfree space 20. This cathode provides a forward iiat annular face copiously emissive of electrons and activated in that respect by suitable means such as a heater coil 25 directly behind the same. A focusing or electron confining element is provided, here shown as coaxial metallic cylindrical walls, one of which, 28, is radially beyond the cathode and substantially alined with the resonator cylindrical wall IB. and the other of which, 21. is radially within the cathode and substantiallyalined with the resonator cylindrical wall I8. Suitable support, such as disc-like insulator 28 is provided for the focusing element. situated at the rear of the cathode and heater both of which may likewise be conveniently mounted from said support.

Except for an annular area defined by the cross-section of the field-free space, the resonator chamber Il is closed at ifs rear end, that is, at its end nearest the cathode, by a rear end metallic wall 29 which is preferably fixed or immovable. While this wall is actually in two parts. namely an outer washer-like section and an inner disclike section in a common plane, those sections are in e'ect an end closure for the chamber and are connected rigidly by a grid 2li across the end of the heid-free space opening at the plane of the wall. The rigidity is augmented by the further supporting effect of another grid Il at the forward end of the held-free space 2li connecting cylindrical walls I8 and I8. Face view for both of these grids may correspond to face view of grid I2 shown in Fig. 2. Said grid I2 is situated at the forward end of the gap 23 between cylindrical walls 2| and 22. It will be noted that said grids as here shown are made up from a plurality of U-shaped metallic elements presenting narrow edges to the electron stream therethrough. The legs of the opposite elements alternate and in most instances are too short to reach the opposite cylindrical wall but in a few instances do reach entirely across the opening and are then secured to the opposite wall or element so as to obtain the desired connection and rigidity. Other grid constructions and means for connecting the walls at opposite peripheries of the grids may be employed.

Beyond the last mentioned grid 32 and situated between cylindrical walls 2| and 22 is an annular metallic reector 23 of trough-like crosssection carried by a cup-like metallic holder 34 from which a lead connection 35 is provided to a glassed lead-in wire 2B passing through a forward end wall 21 closing across cylindrical wall 2|. This enclosing end constituted by end wall l1 and its attached cylindrical wall constitutes the forward or end section oi' the envelope.

In order to permit adjustment of the gap or construction 2l cylindrical walls 2| and 22 and grid 32 are movabiy mounted by providing the forward end wall of the resonator with flexibility. As shown, said forward end wall comprises an annular flexible metallic diaphragm 38 between the outer resonator cylindrical wall I2 and cylindrical wall 2|, and another ilexible but disc-like metallic diaphragm 29 between the inner cylindrical wall 22 and post I9. Of these diaphragms. the outer annular one 38 is sealed vacuum tight at its outer and inner peripheries to walls Il and 2| respectively and constitutes part of the envelope enclosure. The disc-like flexible diaphragm 39 forms a corresponding end wall portion for the resonator chamber and a flexible support for the grid $2.

Spacing of gap or constriction 23 is regulated and maintained by provision of an outwardly directed flange Il on the resonator outer wall I3, a similar flange 4| on the end closure wall 2| with threaded struts I2 perpendicularly positioned between the flanges to hold them apart and tension springs I3 drawing the flanges toward each other as far as permitted by said struts. An output coaxial loop coupling Il is provided from the interior to exterior of the resonator chamber, it being shown as sealed through the outer resonator wall il.

From the foregoing description it will be appreciated that I have provided a structure of electron discharge device wherein are combined the advantages of a reflex hollow body resonator type of electron discharge device with a large area oi' electron discharge and passage adaptable for high power high frequency ultra short wave oscillation.

In use, the cathode is caused to emit electrons throughout the annular plane area thereof, these electrons moving forwardly through the ilrst grid 3U the function of which is primarily for focusing purposes. The electrons then continue forward as a cylindrical beam to and through the gap or constriction 22 where they are varied in velocity to promote bunching thereof. They proceed to the reflector and back to the gap or constriction, traveling in a field-free space between cylindrical walls 2| and 22. On this reiiected passage of the electrons through the constricted space between grids l2 and 3|, the electrons are in bunches and energy is extracted in the resonant chamber and carried oi! for useful purpose by output connection M. The construction enables the resonator to be relatively small but with a relatively large cathode area and electron stream. This accomplishes the production of high power output from the necessarily small resonator for production of ultra short wave output frequency. The structure is simple and yet affords ready tuning without use of diilicult-toconstruct tuning mechanism or bulky and expensive parts, and, above all, accomplishes high power output with simple and easily assembled and adjusted mechanism.

I claim:

1. An electron discharge device comprising an outer cylinder having a fixed end wall at one end thereof and a flexible end wall at the other end thereof and having a tubular passage coaxial with the cylinder through both end walls and spaced both from the axis and from the cylindrical wall, an annular cathode opposite one end of said tubular passage. and an annular reflector at the other end of said passage.

2. An electron discharge device comprising an outer cylinder having a fixed bottom end wall with a concentric annular opening therein, inner cylindrical walls of less height than said outer cylinder concentric with and rising from the peripherles of said annular opening whereby one of said inner cylinders is of less diameter than the other, two upper cylindrical walls of equal diameter t0 and opposite the ends of said inner cylindrical walls, a top wall closing the top of the smaller of the upper cylindrical walls, an annular flexible top wall closing the annular space between the larger of the upper cylindrical walls and the outer cylinder, an annular cathode below the said annular opening. and an annular reflector between the said upper cylindrical walls.

3. An electron discharge device comprising an outer cylinder having a fixed bottom end wall with a concentric annular opening therein, inner cylindrical walls of less height than said outer cylinder concentric with and rising from the peripheries of said annular opening whereby one of said cylinders is of less diameter than the other and an annular passage is formed therebetween, two upper cylindrical walls respectively of equal diameter to and opposite the ends of said inner cylindrical walls and forming a continuation of said annular passage, a exible top wall closing the top oi' the smaller of the upper cylindrical walls and forming therewith and with the bottom wall an inner part of a resonant chamber, an annular flexible top wall closing the annular space between the larger of the upper cylindrical walls and the outer cylinder and i'onning therewith and with the bottom wall an outer part of a resonant chamber, said inner cylindrical walls being spaced at their upper ends away from the lower ends of the said upper cylindrical walls thereby providing a gap connecting said inner and outer resonant chamber parts and constituting therewith a resonant chamber, an annular cathode opposite one end of said annular passage. and an annular redactor opposite the other end of said annular passage.

4. An electron discharge device comprising an outer cylinder having a xed bottom end wall with a concentric annular opening therein, inner 5 cylindrical walls of less height than said cuter cylinder concentric with and rising from the peripheries of said annular opening whereby one of said cylinders is of less diameter than the other and an annular passage is formed therelu between, two upper cylindrical walls respectively of equal diameter to and opposite the ends of said inner cylindrical walls and forming a continuation or said annular passage, a iiexible top wall closing the top oi the smaller oi' the upper cylin- 1,-;

drical walls and forming therewith and with the bottom wall an inner part of a resonant chamber, an annular ilexible top wall closing the annular space between the larger oi' the upper cylinci a resonant chamber. said inner cylindrical walls being spaced at their upper ends away from the lower ends o! the said upper cylindrical walls thereby providing a gap connecting said inner and outer resonant chamber parts and constituting therewith a resonant chamber, an annular cathode opposite the lower end of said annular passage, an annular reflector at the upper end of said passage, an inverted cup-shaped support supporting the reflector extending over the top wall of the inner part o! the resonant chamber, said larger diameter upper cylindrical wall extending to an elevation higher than the said support. a top wall closing said larger diameter cylindrical wall enclosing the space therebeneath, said larger diameter cylindrical wall, annular ilexible top wall and outer cylinder being sealed to i'orm a part of a vacuum tight envelope. and means at the bottom ot said cylinder i'ormlng the compledrical walls and the outer cylinder and forming 2u mental-y partof said envelope.

therewith and with the bottom wall an outer part DAVID GORDON CLIFFORD.

Disclaimer 2,400,743.-Dam3d Gordon Ulij'ord, Palo Alto, Calif. REFLEX KLYs'raoN. Patent dated Ma 2l, 1946. Disclaimer filed Aug. 6, 1949, by the assignee, West- 'inghouse lectnlc Corporation.

Hex-eb enters this disclaimer to claim 1 in said specification.

[ cial Gazette Sept. 6, 1.949.]

passage. and an annular redactor opposite the other end of said annular passage.

4. An electron discharge device comprising an outer cylinder having a xed bottom end wall with a concentric annular opening therein, inner 5 cylindrical walls of less height than said cuter cylinder concentric with and rising from the peripheries of said annular opening whereby one of said cylinders is of less diameter than the other and an annular passage is formed therelu between, two upper cylindrical walls respectively of equal diameter to and opposite the ends of said inner cylindrical walls and forming a continuation or said annular passage, a iiexible top wall closing the top oi the smaller oi' the upper cylin- 1,-;

drical walls and forming therewith and with the bottom wall an inner part of a resonant chamber, an annular ilexible top wall closing the annular space between the larger oi' the upper cylinci a resonant chamber. said inner cylindrical walls being spaced at their upper ends away from the lower ends o! the said upper cylindrical walls thereby providing a gap connecting said inner and outer resonant chamber parts and constituting therewith a resonant chamber, an annular cathode opposite the lower end of said annular passage, an annular reflector at the upper end of said passage, an inverted cup-shaped support supporting the reflector extending over the top wall of the inner part o! the resonant chamber, said larger diameter upper cylindrical wall extending to an elevation higher than the said support. a top wall closing said larger diameter cylindrical wall enclosing the space therebeneath, said larger diameter cylindrical wall, annular ilexible top wall and outer cylinder being sealed to i'orm a part of a vacuum tight envelope. and means at the bottom ot said cylinder i'ormlng the compledrical walls and the outer cylinder and forming 2u mental-y partof said envelope.

therewith and with the bottom wall an outer part DAVID GORDON CLIFFORD.

Disclaimer 2,400,743.-Dam3d Gordon Ulij'ord, Palo Alto, Calif. REFLEX KLYs'raoN. Patent dated Ma 2l, 1946. Disclaimer filed Aug. 6, 1949, by the assignee, West- 'inghouse lectnlc Corporation.

Hex-eb enters this disclaimer to claim 1 in said specification.

[ cial Gazette Sept. 6, 1.949.] 

